Unit 3 Exam

Anatomy

What is the amount of blood contained in the body?

5L

What is the function of the blood/circulatory system?

TRP

Transport - cellular metabolism are transported by the circulatory system

Regulation - blood carries hormones and other regulatory molecules

Protection - protects against injury & foreign microbes or toxins within the body

• Clotting, mechanisms, leukocytes (immunity)

venous blood

• deoxygenated

• found in veins and pulmonary artery

• oxygen-hemoglobin saturation approximately 75%

• darker in color (blue)

arterial blood

• oxygenated, oxyhemoglobin

• found in arteries and pulmonary vein

• oxygen-hemoglobin saturation approximately 97-98%

• bright (red)

Name the lowest plasma protein starting with an ‘F’ and it’s function?

Fibrinogen (4% of total plasma protein)

• Assist thrombocytes in the formation of blood clots

Name the second plasma protein with a ‘G’ and it’s function?

Globulins (36% of all plasma protein)

• Alpha & beta - transport lipids & fat-soluble vitamins

• Gamma - constitute anti-bodies of immunity

Name the third plasma protein with a ‘A’ and it’s function?

Albumin (60-80% of all plasma protein)

• Functions to help maintain osmotic pressure of blood & carries certain molecules to the blood

define agranulocytes & identify the purpose of each and prevalence in the body.

• lack visibility in the cytoplasm

• have spherical or kidney-shaped nuclei

lymphocytes - large purplish, circular nuclei with a thin rim of blue cytoplasm (25-45%)

• mostly in lymphoid tissue, few circulate in the blood

• crucial to immunity

monocytes - the largest leukocyte (3-8%)

• abundant pale-blue cytoplasm

• leave circulation, enter tissues, and differentiate into macrophages

  • actively phagocytic cells; crucial against viruses

  • activate lymphocytes to mount as immune response

define granulocytes & identify the purpose of each and prevalence in the body

Neutrophils - bacterial infection; elevated neutrophil

• most numerous WBCs

• Give the cytoplasm a lilac color

• Very phagocytic - “bacteria slayers”

Eosinophils - red-staining, bi-lobed nuclei

• digest parasitic worms that are TOO large to be phagocytized

Basophils - antihistamines; blocking effects

• Rarest WBCs

• Large, purplish-black (basophilic) granules contain histamine

histamine

an inflammatory chemical that acts as a vasodilator and attracts other WBC to inflamed sites

hemopoiesis

is the name of the process in which blood cells are formed

• Starts with hemocytoblast (stem cell) → for all formed elements

ABO system

AB

• Has both A and B antigens on the surface of red blood cells.

• No anti-A or anti-B antibodies in the plasma.

• universal recipient.

B

• Has the B antigen on the surface of red blood cells

• Anti-A antibody in the plasma.

• Blood that can be received is B, O

A

• Has the A antigen on the surface of red blood cells.

• The anti-B antibody in the plasma.

• Blood that can be received is A, O

O

• Has no A or B antigens on the surface of red blood cells

• Both anti-A and anti-B antibodies in the plasma.

• It's the universal donor.

hemostasis

blood clotting is the mechanism in which injured vessels are repaired in order to control bleeding/blood loss

erythropoiesis

formation of erythrocytes (RBCs)

• estimated that 2.5 million erythrocytes are produced every second in order to replace those destroyed

Myeloid Tissue - red bone marrow

• Humeri

• Femora

• Ribs

• Sternum

• Vertebrae

• Parts of the Skull

  • leuokpoiesis

leukopoiesis

formation of leukocytes (WBCs)

Lymphoid Tissue - lymphatic tissues

• Lymph nodes

• Tonsils

• Spleen

• Thymus

What are the three hemostatic mechanisms discussed?

Breakage of endothelial lining of a blood vessel exposes collagen proteins to the blood initiating…

Vascular Spasm - vasoconstriction of damaged blood vessel; reduced blood flow & minimize blood loss

Platelet Plug Formation

• Positive feedback cycle

• At site of blood vessel injury; platelets:

  • Stick to exposed collagen fibers with the help of plasma proteins

Coagulation

• Blood is transformed from a liquid to a gel

• Reinforces the platelet plug with fibrin

define blood

a vital fluid that circulates through your body, delivering essential substances like oxygen and nutrients to cells, and removing waste products.

• connective tissue of plasma & formed elements

define formed elements

45 - 50% of blood volume

Erythrocytes (RBC) - most numerous blood cell

Leukocytes (WBC) - contain nucleus & mitochondria

Thrombocytes (platelets) - no nucleus

define diapedesis

leukocytes squeeze through capillary walls to enter tissue space outside the blood vessel

define plasma

50 to 55% of total blood volume

• Straw colored liquid containing dissolved substances (liquid left after formed elements are removed)

define plasma proteins

mostly produced by the liver found in (blood) plasma.

Function:

Including transport of lipids, hormones, vitamins, and minerals, as well as immune system activity.

define erythrocytes

• Biconcave (no nucleus); no organelles

• Biconcave shapes increase surface area = increases gas exchange

• No mitochondria: ATP production is anaerobic; no O₂ is used in generation of ATP

• Contains hemoglobin (Hb) which functions to transport oxygen & carbon dioxide within the blood

function of erythrocytes

• Transport oxygen from the lungs to all body tissues.

• Pick up carbon dioxide at the tissues and transport it to the lungs

definition of leukocytes

• Contain nucleus & mitochondria

• Can move in & out of the blood vessels. The name given to this movement

  • Only complete cells of the blood formed elements

function of leukocytes

to aid in defense against infections by micro-organisms

thrombocytes (platelets)

• (cytoplasmic fragments) of large cells (megakaryocytes)

• The phospholipid in their membrane serve to activate the clotting factors in the plasma

function of thrombocytes

to assist the blood clotting mechanisms

epicardium (1st part of heart wall)

visceral layer of the serous pericardium

myocardium (2nd part of heart wall)

• Spiral bundles of cardiac muscle cells

• Fibrous skeleton of the heart: crisscrossing, interlacing layer of connective tissue

  • Anchors cardiac muscle fibers

  • Supports great vessels and valves

  • Limits spread of action potentials to specific paths

endocardium (3rd part of heart wall)

• the continuous of linings blood vessels leaving and entering the heart

• thin smooth membrane which lines the inside of the chambers of the heart and forms the surface of the valves

How does the myocardium differ between the R and L atria and the R and L ventricles?

Atria: The Receiving Chambers

• R and L atria [need to contract only minimal blood for ‘downstairs’]

  • Blood drains back to the heart into the atria

  • Separated internally by the interatrial septum

  • Small, thin-walled structures

Ventricles: The Discharging Chambers

• Two ventricles [massive walls]

  • Separated by the interventricular septum

  • Pumps blood into circulation [out from the heart into circuits

  • Walls are (irregular) ridged by trabeculae carneae

  • Papillary muscles project into the ventricular cavities

chambers of the heart and what it does?

4 chambers of the heart

Right Atrium: Receives deoxygenated blood from the body through the superior and inferior vena cavae.

Right Ventricle: Pumps deoxygenated blood to the lungs via the pulmonary arteries.

Left Atrium: Receives oxygenated blood from the lungs through the pulmonary veins.

Left Ventricle: Pumps oxygenated blood to the body through the aorta.

heart valves and what it does?

Atrioventricular Valves (AV) - prevents backflow of the blood, when ventricles contract

• Tricuspid Valve (Right atrioventricular) - has three flexible flaps of endocardium reinforced by connective tissue cores

• Bicuspid Valve (Mitral valve & left atrioventricular) - with two flaps

Semilunar Valves (SL) - guard the bases of the large arteries issuing from the ventricles

• Pulmonary Semilunar Valve (Right Semilunar) - base of the pulmonary trunk

• Aortic Semilunar Valve (Left Semilunar) -oxygenated blood leaves to the rest of the body

major vessels associated with each chamber and what it does

Right Pump Chamber

Superior & Inferior Vena Cava (vein)

• Deoxygenated blood from body → heart (R atrium)

Pulmonary Artery (away from the heart)

• Deoxygenated blood from heart (R ventricle → pulmonary trunk) → to the lungs

Left Pump Chamber

Pulmonary Vein (back to heart)

• Oxygenated blood from lungs → heart (L atrium)

Aorta (from the heart to the artery)

• Oxygenated blood from heart (L ventricle) to rest of the body

What is the purpose of the heart valves? Understand their precise role during the cardiac cycle.

blood flows in the correct direction through your heart, preventing any backflow and maintaining efficient circulation.

• the opening and closing in response pressure differences that are generated from those mechanical events systole & diastole.

• Basically ‘traffic controllers’ of the cardiovascular system

Identify the circulatory routes for blood flow throughout the body.

• Right side is the pump for the pulmonary circuit (short, low pressure circulation)

  • Vessels that carry blood to & from the lungs

• Left side is the pump for the systemic circuit & coronary circuit (blood encounters much resistance)

  • Vessels that carry blood to & from all body tissues

How is blood carried to and from the myocardium?

The coronary arteries branch off from the aorta and supply oxygen-rich blood to the myocardium.

• irregular pulsating blood flow to the myocardium.

• delivers blood when the heart is relaxed, but ineffective when ventricles are contracting

The coronary veins collect venous blood whose paths roughly follow those of the coronary arteries.

• They join an enlarged vessel called the coronary sinus, which empties the blood into the right atrium.

Understand the cardiac cycle: sequence of events encompassing one complete contraction and relaxation of the atria and ventricles of the heart.

1. Atrial Systole:

   • Atrial contraction forces a small amount of additional blood into relaxed ventricles.

2. Ventricular Systole:

   • Ventricles contract.

   • Blood is pushed out of the right ventricle into the pulmonary artery (to the lungs) and out of the left ventricle into the aorta (to the rest of the body).

   • The atrioventricular valves (tricuspid and mitral) close to prevent backflow into the atria.

3. Atrial Diastole:

   • Atria relax and fill with blood from the veins (vena cavae into the right atrium and pulmonary veins into the left atrium).

   • This phase coincides with ventricular systole.

4. Ventricular Diastole:

   • Ventricles relax after contraction.

   • Blood flows from the atria into the ventricles, filling them in preparation for the next cycle.

   • The semilunar valves (pulmonary and aortic) close to prevent backflow from the arteries.

define arteries

• Large thick-walled arteries with elastin in ALL three tunics.

• Have thick tunica media with more smooth muscle

• Carry blood under relatively high pressure

• Expand & recoil as blood is ejected from the heart

• resistance & distribution vessels

• 15% blood volume distribution

define arterioles

• Smallest arteries

• Lead to capillary beds

• Control flow into capillary beds via vasodilation & vasoconstriction

define capillaries

• Microscopic blood vessels

• Walls of thin intima, one cell thick

• Size allows only a single RBC to pass at a time

• 5%

• (35-15 mm Hg) low pressure

• Exchange vessels

define venules

• Formed when capillary beds unite with the veins.

• Very porous; allow fluids & WBCs into tissues

define veins

Thinner-walled than arteries, with larger lumens.

• They contain valves to prevent backflow and rely on skeletal muscle contractions to help push blood back to the heart.

• venous pumps

• capacity vessels

• 64%

• (15-0 mm Hg) ; low pressure

Why is the capillary conserved to be the “functional unit” of the circulatory system?

their thin walls allow for the exchange of oxygen, nutrients, and waste products between blood and tissues making it the functional unit.

What is the function of the precapillary sphincter?

acts as a valve to regulate blood flow into the capillaries.

• (not innervated) By constricting or relaxing, it controls the amount of blood that reaches the tissues, ensuring that blood is directed to the organs most needed.

Understand the factors that influence filtration and re-absorption between the capillaries and the surrounding tissues.

water & substances leave capillaries because of net outward pressure (arteriole end)

• enter because of net inward pressure (venule end)

diffusion - lipid soluble substances pass directly through

filtration -

• hydrostatic pressure pushes out

• colloid osmotic pressure draws fluid back in

What factors influence peripheral (systemic) resistance?

Blood viscosity

• Greater viscosity, the greater the resistance

Blood vessel length

• Longer the vessel, the greater the resistance

Blood vessel diameter (size of the lumen)

• Smaller the tube, greater the resistance

friction

(opposition to blood flow) b/w blood & vessel wall

What is the order of transmission of the electrical impulses throughout the heart?

1) Sinoatrial (SA) Node: The pacemaker of the heart, located in the right atrium, generates an electrical impulse. (75 times/minute.)

• depolarizes faster than the myocardium

• intrinsic & extrinsic control (ANS)

2) Atrioventricular (AV) Node: The impulse reaches the AV node, where it is briefly delayed (0.1 second) to ensure the atria have fully contracted before the ventricles are stimulated. “electrical bridge”.

• intrinsic & extrinsic control (ANS)

• 50 times/per minute

3) Atrioventricular (AV) bundle: Only electrical connection between the atria & ventricles

4) R & L bundle branches: two pathways in the interventricular septum that carry the impulses toward the apex of the heart

5) Purkinje fibers: complete the pathway into the apex & ventricular walls

• AV bundle & Purkinje fibers depolarize only 30 times/minute in absence of AV

• Ventricular myocardial contraction (systole)

sinus rhythm

determines heart rate

What does the electrocardiogram represent?

ECG or EKG is a composite of all the action potentials generated by nodal and contractile cells at a given time.

• Monitors & amplifies

• graphic record of heart activity

Understand the purpose of the venous valves and the skeletal muscle pump. What is the importance of this pump during exercise?

The purpose of the venous valves during exercise, is the contraction of the skeletal muscles compresses the veins, pushing blood towards the heart and increasing venous return; without it you’ll have a reduce in BP and CO.

• The presence of one-way valves in veins prevents backflow of blood, ensuring that it moves efficiently towards the heart during the muscle pump action.

Understand the relationship between electrical activity, mechanical events, pressure changes, and blood flow in the heart.

depolarization causes systole (contraction), increase in pressure, increase in blood flow.

repolarization causes diastole (relaxation), decrease in pressure, decrease in blood flow.

Identify the various components of waves of the ECG. Which are associated with atrial depolarization? Ventricular depolarization? Atrial repolarization? Ventricular repolarization?

P wave - Represents the contraction of the atria

• Atrial depolarization, initiated by the SA node

QRS complex - Represents the contraction of ventricles.

• Ventricular depolarization - beginning of systole; greater increase in ventricular pressure

• isoventricular contraction - short phase; stays the same until ALL valves reopen

T wave - ventricular repolarization, passive filling, and isoventricular relaxation (relaxed) begins at the apex.

• Relax to prepare for the next contraction.

What is represented by systolic and diastolic blood pressure?

Systolic: This is the top number and represents the pressure in your arteries when your heart beats (contracts) and pumps blood. It’s like the peak pressure your heart generates.

Diastolic: This is the bottom number and represents the pressure in your arteries when your heart is resting between beats. It’s the lowest pressure your arteries experience.

What is hypertension?

also known as high blood pressure, is when the force of your blood against the walls of your arteries is consistently too high

How is venous pressure and venous blood flow maintained?

• Veins can distend to hold a higher volume of blood, which helps maintain central venous pressure.

• These valves ensure unidirectional blood flow, preventing backflow.

• When muscles contract, they squeeze veins and help push blood back toward the heart.

• This decreases venous compliance, increases central venous pressure, and promotes venous return by augmenting cardiac output.

How does walking or jogging after exercise aid circulation recovery?

it helps to enhance blood flow and helps with recovery

What is meant by cardiac output and what is its significance?

amount of blood pumped by each ventricle in one minute

• CO = heart rate (HR) x Stroke volume (SV)

• (L/min) or (ml/min) - (L/beat) or (ml/beat)

• Essential for ensuring that tissues and organs receive enough oxygen and nutrients to meet the body's demands, especially during physical activity.

What are the factors that contribute to stroke volume?

Preload: degree of stretch of cardiac muscle cells before they contract (Frank-Starling law of the heart)

• Increased venous return/volume = increased EDV = increased SV

• decrease in ESV

Contractility: contractile strength at a given muscle length

• Sympathetic stimulation increases contractility (ANS)

• Independent of muscle stretch & EDV

• Increased contractility = increased volume ejected = decrease ESV = increase SV

• CONTRACTILITY affects ESV

Afterload: pressure that must be overcome for ventricles to eject blood

• Hypertension increases afterload, resulting in increased ESV and reduced SV

• Greater arterial pressure to overcome impacts amount of blood ejected

• increased AFTERLOAD impacts increased ESV = decreased SV

define parietal pericardium

is the outer layer of the pericardium, which is the sac that surrounds the heart.

• It provides a protective layer and helps reduce friction between the heart and surrounding structures as the heart beats.

define heart wall

The heart wall, richly supplied with blood vessels, is composed of three layers: the epicardium, myocardium, and endocardium

heart sounds lub-dup

sound is a classic “heartbeat”

AV (atrioventricular) and SL (semilunar) valves closing keeping everything in motion

define sinoatrial node (SA)

The pacemaker of the heart, located in the right atrium, generates an electrical impulse. (75 times/minute.)

define atrioventricular node (AV)

The impulse reaches the AV node, where it is briefly delayed (0.1 second) to ensure the atria have fully contracted before the ventricles are stimulated. “electrical bridge”

purkinje fibers

complete the pathway into the apex & ventricular walls

p wave

Time: 0.1 sec - 12.5%

Mechanical Activity: atrial depolarization (contracts), during ventricular relaxation (ventricular/active filling) initiates the SA node causing the P wave

Valve Position: AV valve (open), semilunar valve (closed)

Blood Flow: From the atria into the ventricles

QRS complex

Time: 0.3 sec - 37.5%

Mechanical Activity: ventricles contract during atrial relaxation (ventricular ejection)

• isovolumetric contraction

• rapid ejection

• reduced ejection

Valve Position: AV valve (closed), semilunar valve (open)

Blood Flow: From the ventricles into the arteries

t wave

Time: 0.4 sec - 50%

Mechanical Activity: atrial & ventrical relaxation (ventricular filling)

• isoventricular filling

• isoventricular relaxation

• passive filling

Valve Position: AV valve (open), semilunar valve (closed)

Blood Flow: from the veins → to the atria → ventricles